When Levon Helm and The Band hosted a five-hour send-off concert in 1976, it was a musical event of mythic proportions. The Band and its guests—among them Bob Dylan, Neil Young, and Joni Mitchell—were torchbearers of the American folk revival. And though it might be overly dramatic to say the movement “ended” with The Last Waltz, it was just a few years later that folk, blues, and gospel-soul began yielding pop to the second British invasion, arena rock, grunge, and hip-hop.

It would be likewise overdramatic to equate Sunday’s Route 29 Revue at Merriweather to The Last Waltz—certainly in terms of importance. But those attendees who’ve made a religious custom of watching the eponymous Scorcese film could not deny the aesthetic similarities. Old Crow Medicine Show, Iron and Wine, the Felice Brothers, and Grace Potter and the Nocturnals are very much torchbearers of the second folk revival, the one that began in the mid-’90s and has broadened in the new millenium thanks to the Web revolution and the consequent fragmentation of pop. Presiding over Sunday’s festival was Helm, the godfather.

Local boy (well, Virginian) Justin Jones opened with a set that was more modern country-pop than throwback country-folk, but that gave way to the barn-burning bonhomie of the Felice Brothers, an outfit of Yankee good ol’ boys from upstate New York. The Felice Brothers honed their chops in juke joints and subway stations and recorded their first two albums in a chicken coop, so they seemed out a bit out of place on the Merriweather stage. But it was clear right away that we were to play by their rules. Everybody was out of their seats by the second song, clapping and singing along to “Whiskey in My Whiskey,” “Run Chicken Run,” and Townes Van Zandt’s “Two Hands”—struggling all the while to match the energy of the band, whose members would run in circles, crash into each other, and take turns dancing on top of the kick drum (occasionally whaling on the cymbals with a washboard).

Grace Potter and the Nocturnals assumed a more formal stage presence—with the mic stands adorned with rose bouquets and Potter herself fit for the prom in a pale-gold gown—but their set was no less boisterous. Grace and the Nocs, who intersect with American roots music at the corner of Raitt and Joplin (oft-cited analogs, but undeniable ones), played a mostly uptempo set culminating in the title track(s) from the band’s first major-label (re-)release—a high-energy organ jam bookended by an a cappella intro/outro that would be called gospel if its lyrics didn’t eschew God and the Bible in favor of Water. Call it green gospel. Did I mention the band’s from Vermont?

Poor Sam Beam (aka Iron and Wine) came on next to play what was effectively an intermission between two halves of a hootenanny. Dressed neatly in khakis a white button-down—which, combined with his trademark beard, made him look like Happy Gilmore’s caddy—Beam seemed a little embarrassed to follow Potter’s dam-bursting water anthem with his gossamer lullabies. The result was a lot of grace notes and a chest-voice croon that gave whispery cradlesongs like “Upward Over the Mountain” and “The Trapeze Swinger” a more soulful presence in lieu of a backing band. (Where are the Calexico boys when you need them?)

Levon and his entourage—among them his daughter, Amy, and fellow Dylan collaborator Larry Campbell (who produced Helm’s new album, Electric Dirt)—came on next to remind the audience where all that second-wave folk stuff had come from. In the night’s only real disappointment, Levon declined to sing, per orders from his doctor. But, as City Paper Web editor and fellow concertgoer Ted Scheinman aptly put it, “Thank God for Larry Campbell.” Campbell led the band (which also featured Levon’s Midnight-Ramble horn section and E Street Band/Conan O’Brien multi-instrumentalist Jimmy Vivino) in a set that included four Band classics—“Long Black Veil,” “The Shape I’m In,” “It Makes No Difference,” and “Chest Fever”—the last featuring Campbell in a spine-chilling guitar imitation of Garth Hudson’s diabolical organ intro. With Levon’s vocal chords out of commission, they stayed away from songs such as “The Weight” and “Ophelia,” a wise and respectful choice (to sing “The Weight” without Levon would have been sacrilege, even with his blessing).

Levon kept time on drums and played a bit of mandolin, but his primary function at the Revue was to preside over the celebration of a tradition he and his contemporaries helped shape. In the middle of his set, the 69-year-old icon took a breather while his daughter, Campbell, and Campbell’s wife Teresa Williams sang a three-part harmony to the Grateful Dead ballad “Attics of my Life.” It was, perhaps, the unlikely highlight of the set; reverly turned to reverence as the trio sang, “I have spent my life seeking all that’s still unsung / Bent my ear to hear the tune, and closed my eyes to see / When there was no strings to play, you played to me.” In the shadows offstage, Levon was sitting with his eyes closed, rolling his head in slow circles, smiling.

Old Crow Medicine Show closed the six-hour circus with a typically charismatic hoedown, frontmen Ketch Secor and Willie Watson filling the song breaks by yammering back and forth in a schtick that harks back to the snakeoil salesmen from whom they drew their name. The Felice Brothers, who had been touring with Old Crow all summer, slipped on and off stage intermittently throughout the set, which reached a pitch with heel-stompers “Shack #9” and “Minglewood Blues.”

The restless ticketholders had left the back half of the pavilion empty by the time the concert was approaching its eighth hour, and those who remained pushed in toward the stage. Before the musicians closed with “Wagon Wheel”—very much the missing link of post-WWII folk, co-written by Old Crow and Bob Dylan—the day of solidarity culminated as Ian Felice joined Secor at the mic for the slow-paced ballad “We’re All In This Together.” One sensed they were not just singing to their bandmates.

Photo courtesy of Flickr user PZAO.